Lecture 6 - Structure of Dicot and Monocot Root | Plant Anatomy - Biotechnology Engineering (BT) PDF Download

 Page 1


 
Monocot and Dicot Root 
Institute of Life Long Learning, University of Delhi 
 
0 
                                                                                              
 
Lesson Prepared Under MHRD project “National Mission on 
Education Through ICT” 
 
Discipline: Botany 
Paper: Plant Anatomy 
 
National Coordinator: Prof. S.C. Bhatla 
 
Lesson: Monocot and Dicot Root  
Lesson Developer: Dr Nellie Laisram, Dr Anita Rani and   
Dr Arun Kumar Maurya 
Department/College: Dyal Singh College 
 
Lesson Reviewer: Prof. S.C. Bhatla 
Department/College: Department of Botany, University of Delhi 
 
Language Editor: Dr Sonal Bhatnagar 
Department/College: Hindu College 
 
 
Lesson Editor: Dr Rama Sisodia, Fellow in Botany ILLL
Page 2


 
Monocot and Dicot Root 
Institute of Life Long Learning, University of Delhi 
 
0 
                                                                                              
 
Lesson Prepared Under MHRD project “National Mission on 
Education Through ICT” 
 
Discipline: Botany 
Paper: Plant Anatomy 
 
National Coordinator: Prof. S.C. Bhatla 
 
Lesson: Monocot and Dicot Root  
Lesson Developer: Dr Nellie Laisram, Dr Anita Rani and   
Dr Arun Kumar Maurya 
Department/College: Dyal Singh College 
 
Lesson Reviewer: Prof. S.C. Bhatla 
Department/College: Department of Botany, University of Delhi 
 
Language Editor: Dr Sonal Bhatnagar 
Department/College: Hindu College 
 
 
Lesson Editor: Dr Rama Sisodia, Fellow in Botany ILLL
 
Monocot and Dicot Root 
Institute of Life Long Learning, University of Delhi 
 
1 
 
Table of Contents  
Chapter: Monocot and Dicot Root 
? Introduction 
? Tap root system 
? Fibrous root system 
? Adventitious root system 
? Modification of roots on the basis of function 
? Modifications of tap root system  
? Modifications of Adventitious Root  
? Mycorrhiza 
? Ectomycorrhiza 
? Endomycorrhiza 
? Root Nodule 
? Primary structure of root 
? Anatomy of Dicotyledonous root 
? Anatomy of Monocotyledonous Root 
? Economic importance 
? Summary          
? Glossary    
? Exercise 
? References
Page 3


 
Monocot and Dicot Root 
Institute of Life Long Learning, University of Delhi 
 
0 
                                                                                              
 
Lesson Prepared Under MHRD project “National Mission on 
Education Through ICT” 
 
Discipline: Botany 
Paper: Plant Anatomy 
 
National Coordinator: Prof. S.C. Bhatla 
 
Lesson: Monocot and Dicot Root  
Lesson Developer: Dr Nellie Laisram, Dr Anita Rani and   
Dr Arun Kumar Maurya 
Department/College: Dyal Singh College 
 
Lesson Reviewer: Prof. S.C. Bhatla 
Department/College: Department of Botany, University of Delhi 
 
Language Editor: Dr Sonal Bhatnagar 
Department/College: Hindu College 
 
 
Lesson Editor: Dr Rama Sisodia, Fellow in Botany ILLL
 
Monocot and Dicot Root 
Institute of Life Long Learning, University of Delhi 
 
1 
 
Table of Contents  
Chapter: Monocot and Dicot Root 
? Introduction 
? Tap root system 
? Fibrous root system 
? Adventitious root system 
? Modification of roots on the basis of function 
? Modifications of tap root system  
? Modifications of Adventitious Root  
? Mycorrhiza 
? Ectomycorrhiza 
? Endomycorrhiza 
? Root Nodule 
? Primary structure of root 
? Anatomy of Dicotyledonous root 
? Anatomy of Monocotyledonous Root 
? Economic importance 
? Summary          
? Glossary    
? Exercise 
? References
Monocot and Dicot Root 
Institute of Life Long Learning, University of Delhi 2 
Introduction 
Roots serve as the principal organ for water and mineral absorption. It also helps in 
anchoring the plant to its substratum and acts as a major  source of reserve food material 
such as in, fleshy root of carrot (Daucus), radish (Raphanus), beetroot (Beta vulgaris), sweet 
potato (Ipomoea) and yam (Dioscorea). Such roots may also show anomalous secondary 
growth. The radicle that grows out of seed gives rise to root and its primary system, from 
where secondary lateral roots develop. Two types of root systems have been classified on the 
basis of origin of roots which are as follows: 
? Tap root system 
? Fibrous root system 
Tap root system  
It develops from the apical meristem of the embryo (radicle). In majority of plants, radicle 
directly prolongs to form primary root. When primary root is easily distinguishable, it is called 
as tap root system. Later on, it undergoes secondary growth and can penetrate deeply into 
the soil. 
 
 
 
 
 
 
 
 
 
 
Figure: Diagrammatic representation of tap root system; A) Fibrous root, B) Tap root and C) 
Tap root showing primary and secondary roots. 
Page 4


 
Monocot and Dicot Root 
Institute of Life Long Learning, University of Delhi 
 
0 
                                                                                              
 
Lesson Prepared Under MHRD project “National Mission on 
Education Through ICT” 
 
Discipline: Botany 
Paper: Plant Anatomy 
 
National Coordinator: Prof. S.C. Bhatla 
 
Lesson: Monocot and Dicot Root  
Lesson Developer: Dr Nellie Laisram, Dr Anita Rani and   
Dr Arun Kumar Maurya 
Department/College: Dyal Singh College 
 
Lesson Reviewer: Prof. S.C. Bhatla 
Department/College: Department of Botany, University of Delhi 
 
Language Editor: Dr Sonal Bhatnagar 
Department/College: Hindu College 
 
 
Lesson Editor: Dr Rama Sisodia, Fellow in Botany ILLL
 
Monocot and Dicot Root 
Institute of Life Long Learning, University of Delhi 
 
1 
 
Table of Contents  
Chapter: Monocot and Dicot Root 
? Introduction 
? Tap root system 
? Fibrous root system 
? Adventitious root system 
? Modification of roots on the basis of function 
? Modifications of tap root system  
? Modifications of Adventitious Root  
? Mycorrhiza 
? Ectomycorrhiza 
? Endomycorrhiza 
? Root Nodule 
? Primary structure of root 
? Anatomy of Dicotyledonous root 
? Anatomy of Monocotyledonous Root 
? Economic importance 
? Summary          
? Glossary    
? Exercise 
? References
Monocot and Dicot Root 
Institute of Life Long Learning, University of Delhi 2 
Introduction 
Roots serve as the principal organ for water and mineral absorption. It also helps in 
anchoring the plant to its substratum and acts as a major  source of reserve food material 
such as in, fleshy root of carrot (Daucus), radish (Raphanus), beetroot (Beta vulgaris), sweet 
potato (Ipomoea) and yam (Dioscorea). Such roots may also show anomalous secondary 
growth. The radicle that grows out of seed gives rise to root and its primary system, from 
where secondary lateral roots develop. Two types of root systems have been classified on the 
basis of origin of roots which are as follows: 
? Tap root system 
? Fibrous root system 
Tap root system  
It develops from the apical meristem of the embryo (radicle). In majority of plants, radicle 
directly prolongs to form primary root. When primary root is easily distinguishable, it is called 
as tap root system. Later on, it undergoes secondary growth and can penetrate deeply into 
the soil. 
 
 
 
 
 
 
 
 
 
 
Figure: Diagrammatic representation of tap root system; A) Fibrous root, B) Tap root and C) 
Tap root showing primary and secondary roots. 
Monocot and Dicot Root 
Institute of Life Long Learning, University of Delhi 3 
Source: A) http://www.britannica.com/EBchecked/topic/205960/fibrous-root-system 
 B) http://leavingbio.net/flowering%20plants.htm#_Tap_Roots 
 
Fibrous root system  
It is a homogenous system composed of large number of roots of equal size. The radical 
branches divides repeatedly and develops many roots at the same time. Thus, primary root 
cannot be distinguished. 
When roots arise from any part of the plant body other than radicle, it is called as 
adventitious root system. These roots originate from stem, branches, leaves and are 
commonly occur in monocots. Such types of roots are also found in many dicots, namely 
clover (Trifolium), ivy (Hedera), strawberry (Fragaria) and willow (Salix). Most aerial roots 
and stilt roots are adventitious in nature. In some conifers, adventitious roots can form the 
largest part of the root system. The adventitious type of root system in monocotyledons 
arises on the shoot or on the older parts of root 
 
Figure: Adventitious roots in A) Epipremnum aureum and B) Ivy (Hedera helix)  
Source: A) http://www4.uwsp.edu/biology/courses/botlab/lab07b.htm 
B) http://visualsunlimited.photoshelter.com/image/I0000.m1buu_HPns 
Page 5


 
Monocot and Dicot Root 
Institute of Life Long Learning, University of Delhi 
 
0 
                                                                                              
 
Lesson Prepared Under MHRD project “National Mission on 
Education Through ICT” 
 
Discipline: Botany 
Paper: Plant Anatomy 
 
National Coordinator: Prof. S.C. Bhatla 
 
Lesson: Monocot and Dicot Root  
Lesson Developer: Dr Nellie Laisram, Dr Anita Rani and   
Dr Arun Kumar Maurya 
Department/College: Dyal Singh College 
 
Lesson Reviewer: Prof. S.C. Bhatla 
Department/College: Department of Botany, University of Delhi 
 
Language Editor: Dr Sonal Bhatnagar 
Department/College: Hindu College 
 
 
Lesson Editor: Dr Rama Sisodia, Fellow in Botany ILLL
 
Monocot and Dicot Root 
Institute of Life Long Learning, University of Delhi 
 
1 
 
Table of Contents  
Chapter: Monocot and Dicot Root 
? Introduction 
? Tap root system 
? Fibrous root system 
? Adventitious root system 
? Modification of roots on the basis of function 
? Modifications of tap root system  
? Modifications of Adventitious Root  
? Mycorrhiza 
? Ectomycorrhiza 
? Endomycorrhiza 
? Root Nodule 
? Primary structure of root 
? Anatomy of Dicotyledonous root 
? Anatomy of Monocotyledonous Root 
? Economic importance 
? Summary          
? Glossary    
? Exercise 
? References
Monocot and Dicot Root 
Institute of Life Long Learning, University of Delhi 2 
Introduction 
Roots serve as the principal organ for water and mineral absorption. It also helps in 
anchoring the plant to its substratum and acts as a major  source of reserve food material 
such as in, fleshy root of carrot (Daucus), radish (Raphanus), beetroot (Beta vulgaris), sweet 
potato (Ipomoea) and yam (Dioscorea). Such roots may also show anomalous secondary 
growth. The radicle that grows out of seed gives rise to root and its primary system, from 
where secondary lateral roots develop. Two types of root systems have been classified on the 
basis of origin of roots which are as follows: 
? Tap root system 
? Fibrous root system 
Tap root system  
It develops from the apical meristem of the embryo (radicle). In majority of plants, radicle 
directly prolongs to form primary root. When primary root is easily distinguishable, it is called 
as tap root system. Later on, it undergoes secondary growth and can penetrate deeply into 
the soil. 
 
 
 
 
 
 
 
 
 
 
Figure: Diagrammatic representation of tap root system; A) Fibrous root, B) Tap root and C) 
Tap root showing primary and secondary roots. 
Monocot and Dicot Root 
Institute of Life Long Learning, University of Delhi 3 
Source: A) http://www.britannica.com/EBchecked/topic/205960/fibrous-root-system 
 B) http://leavingbio.net/flowering%20plants.htm#_Tap_Roots 
 
Fibrous root system  
It is a homogenous system composed of large number of roots of equal size. The radical 
branches divides repeatedly and develops many roots at the same time. Thus, primary root 
cannot be distinguished. 
When roots arise from any part of the plant body other than radicle, it is called as 
adventitious root system. These roots originate from stem, branches, leaves and are 
commonly occur in monocots. Such types of roots are also found in many dicots, namely 
clover (Trifolium), ivy (Hedera), strawberry (Fragaria) and willow (Salix). Most aerial roots 
and stilt roots are adventitious in nature. In some conifers, adventitious roots can form the 
largest part of the root system. The adventitious type of root system in monocotyledons 
arises on the shoot or on the older parts of root 
 
Figure: Adventitious roots in A) Epipremnum aureum and B) Ivy (Hedera helix)  
Source: A) http://www4.uwsp.edu/biology/courses/botlab/lab07b.htm 
B) http://visualsunlimited.photoshelter.com/image/I0000.m1buu_HPns 
Monocot and Dicot Root 
Institute of Life Long Learning, University of Delhi 4 
Modifications of roots on the basis of function 
Root modifications helps in performing additional functions and can be seen in both tap root 
and fibrous root systems. 
Modifications of tap root system 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Figure: Modifications of tap root system: A) Conical root (Daucus); B) Fusiform root 
(Raphanus sativa); C) Napiform root (Beta vulgaris); D) Tuberous root (Ipomoea batatas) 
and E) Breathing root (Rhizophora). 
 
Source: (A-C) http://www.pinegreenwoods.com/theswollenroots.htm 
D) http://www.thefooddoctor.com/Sweet-potato-and-goats%E2%80%99-cheese-
mash-Ahealth_recipes_/ 
E)  http://www.examplesof.net/2013_09_01_archive.html